Crusher device comprising an overload safety device

1. A crusher device, the crusher device comprising:

a shaft defining a first direction parallel to its length, the shaft comprising an upper shaft end;

a bearing mounted to the upper shaft end;

a crusher head supported on the bearing; and

an overload safety device coupling the crusher head to the upper shaft end, the overload safety device comprising a biasing device configured to bias the crusher head away from the upper shaft end in the first direction, the biasing device being configured to return the crusher head from a displaced position to an equilibrium position, wherein:

the overload safety device is configured to permit displacement of the crusher head along the first direction relative to the shaft in response to a force acting on the crusher head in the first direction,

the overload safety device further comprises a joint positioned to be supported on the bearing and a top element securely attached to the crusher head,

wherein the biasing device is a bladder accumulator including a bladder disposed between the top element and the joint to bias the crusher head away from the upper shaft end of the shaft.

2. The crusher device of claim 1 , wherein the bearing is a spherical bearing, and the joint is a spherical joint.

3. The crusher device of claim 1 ,

wherein the joint and the top element cooperate to define a cavity which contains a liquid which surrounds the bladder; and

wherein the bladder is configured to hold a pressurized gas such that it is compressible by a relative movement between the joint and the top element due to the force acting on the crusher head in the first direction.

4. The crusher device of claim 1 , wherein the overload safety device is configured to provide a soft return of the crusher head from a displaced position, so that the return is dampened as compared to the displacement.

5. The crusher device of claim 1 , wherein the crusher head is affixed to the top element.

6. The crusher device of claim 1 , wherein the biasing device is configured to bias the top element away from the joint.

7. The crusher device of claim 1 , wherein the crusher head is moveable in the first direction relative to the joint.

8. The crusher device of claim 1 , wherein the crusher head abuts the joint and is moveable in the first direction relative to the joint.

9. The crusher device of claim 1 , wherein the crusher head abuts the joint and is moveable in the first direction relative to the joint, and wherein the crusher head is not moveable relative to the joint in a plane perpendicular to the first direction.

10. The crusher device of claim 1 , wherein the bearing is configured so as to allow the crusher head to rotate relative to the shaft, or the bearing and the joint cooperate to allow the crusher head to rotate relative to the shaft.

11. The crusher device of claim 1 , further comprising an eccentric configured to be rotated about the shaft, wherein the crusher head is disposed around the eccentric such that rotation of the eccentric causes gyratory movement of the crusher head, and wherein the crusher head is moveable along the first direction relative to the eccentric in response to the force.

12. The crusher device of claim 1 , further comprising an upper housing, wherein the crusher head and the upper housing together define a crushing gap, and wherein the overload safety device permits displacement of the crusher head along the first direction relative to the shaft in response to a force acting on the crusher head in the first direction thereby changing the size of the crushing gap.